To improve the efficiency of
train working, train controllers (also known as controllers, district controllers, line controllers and area controllers) were progressively introduced on many British-style railways in the early years of the 20th century, the first being on the
Midland Railway in 1907. Although the specifics of their duties varied between railways, train controllers were responsible for tracking train movements (especially freight), ensuring
freight trains were loaded economically and provided with suitable locomotive power, liaising with train crew rostering personnel, ordering additional trains to run for the carriage of extra freight tonnage or passengers as required, allocating paths for unscheduled services and making alterations to scheduled working in order to maximize efficiency and deal with any irregularity in traffic which may affect smooth operation. On busy railways such as the Midland, it was at times very difficult for signalmen to keep track of train movements and make optimal traffic regulation decisions whilst operating signalling equipment. Consequently, fast trains could be delayed by slower trains on the line ahead. Moreover, there was no-one with specific responsibilities relating to the efficient, economical use of rolling stock in traffic, which made it difficult to manage the contingencies of underutilisation, wastage and allocation of inappropriate locomotive power. In the face of rising costs, operating economies were particularly important to the private British railway companies in the early twentieth century. The Train Controller was intended to manage these and other difficulties. While Train Controllers were responsible for traffic regulation within their areas of control, they generally had no safety-critical responsibilities, which were within the realm of the signalmen and
station masters.
Method of working Typically, train controllers were stationed at district or "divisional" control offices which were linked by omnibus circuit
telephone systems with selective code rings, to all signal boxes in the area. This method of operating was sometimes known as the Telephone Train Control System. If the signalman required directions, he simply lifted the receiver and spoke to the train controller on the omnibus circuit. If the train controller wanted to issue instructions or receive train arrival and departure times, he selected the relevant signal box on his telephone, which rang the control phone therein. There were two main problems with this system. Firstly, the train controllers could become overloaded with path requests from signalmen, train recording and other duties. This led to delays for signalmen waiting for their turn to speak on the omnibus circuit, making the role of the train controller somewhat self-defeating. Secondly, signalmen were often in a better position to make train working decisions by virtue of their experience and by being on the spot, but were prevented from doing so by bureaucratic procedures. In silent admission of the deficiencies of this system, signalmen were generally left to their own devices, especially in the event of a general disruption to train services, during which the train control system simply could not handle the demands placed upon it. In exceptional cases, district control offices were abandoned and train controllers appointed at key signal boxes (as in the
London Midland Region of
British Railways in the late 1960s), obviating the need for telephonic communication. This practice was followed by what has been the norm since the introduction of modern power signalling schemes, viz. the traditional train controller's substitution by a senior signalman, signal box supervisor or traffic regulator, situated in the signal box.
Power signal boxes In the UK, the beginning of the end for classic "Control" came with the commissioning of large
power signal boxes from the 1950s. A power signal box (PSB) often has a number of signalmen operating multiple electric or computerized signalling panels and large illuminated track diagrams showing wide areas of operation. This makes traffic regulation much easier for signalmen to handle among themselves. In some cases, a traffic regulator is appointed, who may be consulted for train working decisions. Following the accident at
Ladbroke Grove in 1999, it was resolved that supervisors should be appointed at key signal boxes. However, these supervisors are not train controllers. Similar appointments have been made at major signal boxes in
New South Wales since 2012. == See also ==